Fuze



Fb. 17, 1959 c. c. LAuRrrsl-:N 2,873,681

FUZE

Filed Feb. 3. 1945 uw vm mn W .om NN MN wm mm N S ATTORNEY v ,Q w

United StatesA PatentZ4 O anzu charles c. Laut-teen, Pasadena, Calif.,assignmto the United States of America as represented by the Sec retaryof the Navy This invention relates to fuzes and particularly 'to basefuzes for rocket projectiles. In a typical installation a fuze of myinvention is `interposed between the bomb portion and the motor portionof the rocket projectile and utilizes the gas pressure created in thenormal operation of the rocket motor for arming. Several advantages ofsuch an installation are immediately seen. For example, since the fuzeis not dependent upon any external agency for its operation, it may becompletely enclosed in the rocket assembly thus offering no resistanceto travel of the projectile assembly through the air. Also, the greatgas pressure built up in the rocket motor and conducted to the fuze forits operation permits the fuze to be ruggedly constructed withoutdecreasing its reliability or sensitivity.

An object of the invention, therefore, is to provide a rocket projectilefuze of sturdy construction which will arm .only under pressure of thegases produced by the combustion of the rocket propellant.

Another object of the invention is to provide a fuze which will arm onlyafter it has travelled a safe predetermined distance from the launchingmechanism.

Still another object of the present invention is to provide a rocketprojectile fuze operable with none of its components exposed to the air.

For a more complete understanding of the invention, together with otherobjects and advantages thereof, reference may be had to the .followingspecifications and drawings in which:

Fig. 1 is a longitudinal sectional view of a fuze representing apreferred embodiment of the invention;

Fig. 2 is a sectional view taken along line 2-2 of Fig. 1;

Fig. 3 is a sectional view taken along line 3-3 of Fig. 1;

Fig. 4 is a sectional view taken along line 4 4 of Fig. l;

The fuze includes an adapter fitting provided with internal threads 11to receive the tube of a rocket motor 12 and external threads 13 whichscrew into the base of a bomb case 14 or the like. Adapter fitting 10 isprovided With an annular groove 15 which receives a ange 16 of diaphragm17. The diaphragm is sealed and secured at its circumference to adapterfitting 10 by solder joint 18 and is additionally held by the skirt of acupshaped partition member 19 which is screwed into internal threads 11ahead of the rocket motor 12. Chamber 20 is dened by diaphragm 17 andpartition member 19. Inlet screw 21 provides air communication throughpartition member 19 by means of ports 22 and 23. Inlet screen 24, heldtightly under washer 25 by inlet screw 21, acts as a filter to preventthe entrance of debris into ports 22 and 23.

The base ofl adapter fitting 1t) receives a hollow casing 26 of smallerdiameter than the adapter fitting. Fitted into the extreme forward endof casing 26 is a booster cup 27, the interior end of which is coveredby partition 28 having a lead-in 29 of tetryl or the like. Spacer ring2,873,681 v Patented Feb. 17,1959

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30 and partition 31 define, with partition 28,`a shutter vchamber 32.Booster cup 27 serves as a retaining nut to hold partitions 28 and 31and spacer ring 30 in position. Shutter chamber 32 accommodates shutter33, best shown in Fig. 2, which is mounted on pivot pin 34. A spring 36wound around pivot pin 34 tends to move shutter 33 clockwise from theposition shown in Fig. 2, but is prevented from doing so by theprotrusion of firing pin 37 through guide hole 38 in `partition 31 andinto shutter chamber 32. A spring-loaded detent 39 is carried by shutter33 and engages detent hole 40 in partition 31 when the shutter is in thearmed position. Detonator 41 is carried by shutter 33 and is sopositioned that it is Valigned with firing pin 37 and lead-in 29 whenthe shutte Yis inthe armed position.

Firing pin 37 is screwed into or formed integrally with a firing pinblock 42 which is slidably mounted in the middle portion of casing 26. Aspring 43 is initially compressed and interposed -between shoulder 44 onfiring pin block 42 and the partition 31. Firing pin block 42 isinitially restrained in a forward position by key balls such as 46, onlyone of which is shown in Fig. l, disf posed partly in radial openings 47in the rearward end ofthe firing pin block, and partly in matchingradial openings 48 in casing 26. The latter openings may be closed andadjusted for depth by set screws 49. In this position of firing pinblock 42, firing pin 37 protrudes from partition 31 to restrain theshutter 33. The key balls 46 are restrained in their locking position bylocking rod 49a mounted coaxially and slidably within socket 50 oftiring pin block 42. A constriction 51 on the exterior of locking rod49a affords an escape inwardly for the key balls 46 when theconstriction is moved opposite the. latter. This action releases thefiring pin block 42. The locking rod 49a is provided with a head 52positioned for engagement by diaphragm 17. A shear wire 53 extendsthrough casing 26 and locking rod 49a to prevent premature motion of thelatter. Slits .54 in firing pin block 42 and port 56 in locking rod 49aprevent compression of air behind those parts when they are moved in thenormal operation of the fuze.

The fuze of the invention operates as follows: Initially the fuze is inthe unarmed position shown in Fig. 1. When the rocket motor 12 is red,the pressure due to burning of the propellantnin the rocket motor isapplied to the side of diaphragm 17 exposed to chamber 20 causing thediaphragm to collapse. This does not take place immediately sincechamber 20 is relatively large and ports 22 and 23 are small. The amountof the time delay thus introduced in therefore dependent upon thedimensions of chamber 20 and ports 22 and 23, and upon the strength ofdiaphragm 17. A diaphragm designed to collapse at 500 pounds per squareinch has been found suitable. The shape of the diaphragm is such thatwhen it is forced past a neutral or center point, it snaps into itscollapsed position. When the diaphragm collapses, the locking rod .49asevers shear wire 53 and is forced axially into chamber 50 of firing pinblock 42 bringing constriction 51 opposite key balls 46. Thereupon, thelatter move radially inward into the constriction 51, leaving tiring pinblock 42 free to move in the direction of the diaphragm 17 under thecombined forces of acceleration and spring 43. Firing pin 37 is thuswithdrawn from shutter chamber 32, permitting shutter 33 to move intothe armed position. Thereafter, when the bomb strikes a target, thefiring pin block 42, moving forward in the fuze under its own inertia,drives firing pin 37 into detonator 41 which, in turn, detonates lead-in29 and the booster charge in booster cup 27. v

While what has been described is particularly illustrative of apreferred embodiment of my invention, it is not intended that the scopeof the invention be limited thereto but that it embrace anymodifications and changes which fall within the true spirit of theinvention, as covered by the appended claim, occurring to those skilled.in the art.

I claim: Afuze mount consisting vof atitting deeply recessed and 'having'a central opening leading to 4the recess, a 'cupshapedpartition mem'bersecured in one end of the'tting .and having a cup-flange .extending into'the recess, the

partition portion of the member having a port, .a snapaction diaphragmclamped between the itting ,and said membem being distanced from each toderiue a space next to `the iitting and a chamber next to thepartitionportion with which chamber the port is in communicaftion, afuzehaving. acasing secured Yin the central'opening and carrying a detonator,aIlocking rod slidable in the casing, yhavingone end crossing Vthe spaceto .Contact the diaphragm, a Vtiring pin having means for urging it intoan armed position with respect to the detonator,

Aand `latch"meansinitially restraining the ring'pin from assuming itsarmed position, being held in the restrained position by the lock roduntil displacement of the lock rod by permanent collapse of thediaphragm into the space by an accumulation of pressure gas in thechamber through said port.

References Cited inithe tile of this patent UNITED STATES PATENTS

